From patchwork Tue Apr 27 16:13:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Xu X-Patchwork-Id: 12226911 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 600E6C43460 for ; Tue, 27 Apr 2021 16:14:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0C334600CC for ; Tue, 27 Apr 2021 16:14:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0C334600CC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 220256B00A1; Tue, 27 Apr 2021 12:14:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 10BB96B00A4; Tue, 27 Apr 2021 12:14:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E02926B00A6; Tue, 27 Apr 2021 12:14:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0166.hostedemail.com [216.40.44.166]) by kanga.kvack.org (Postfix) with ESMTP id B57E66B00A4 for ; Tue, 27 Apr 2021 12:14:06 -0400 (EDT) Received: from smtpin35.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 6ECCA5DE9 for ; Tue, 27 Apr 2021 16:14:06 +0000 (UTC) X-FDA: 78078643692.35.CEAD747 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf21.hostedemail.com (Postfix) with ESMTP id 9FDCEE000128 for ; Tue, 27 Apr 2021 16:14:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619540045; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pWfJd/H/T26cGeSLT9ABJVI8Det1WDmJfdLZOnVj/9Y=; b=bwsm8rlCDRmRkWoOk8M/OgoxPrdIwH31gPDE3nml4kTyCPKANHlpYOzlMdB5fF/3PYH9+Q qwIl18lNESYwS8VaIAAnIfAZatLXDRORx6N6NgSWcUJZlZCJBxQmi+X5yi27FJYeJ2SPoM W/mBhmDMQYwKeEtSnuDtBm2UKT2m6jg= Received: from mail-qv1-f71.google.com (mail-qv1-f71.google.com [209.85.219.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-330-v4Z_7boPNDOBhTMmIWbtdg-1; Tue, 27 Apr 2021 12:14:01 -0400 X-MC-Unique: v4Z_7boPNDOBhTMmIWbtdg-1 Received: by mail-qv1-f71.google.com with SMTP id l19-20020a0ce5130000b02901b6795e3304so6666720qvm.2 for ; Tue, 27 Apr 2021 09:14:01 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=pWfJd/H/T26cGeSLT9ABJVI8Det1WDmJfdLZOnVj/9Y=; b=dSszAYwhqenfuIy6c+cbshauFmoX3OSMiOZtcf8HSjNmeZYCyvaV30+LuPAXLUXkDK JgHLeLyLCSFs0O1XfPUpLpZAPmu2DnJ/TfJzGmpGXXguaAsxSmgVR9oEZevs2BEMj95V DtiSBF8vJDyYLYLn9X1GrNnYihRUs4NunyTkqHcnNhCj7oIsk1IJP3NDv/8DFksnc0oy TmOlD6f62pabz7juvduhnMSkq1ZDfPfRcHrCdPz1/3C8nDcbQypb70U3ueu+2CN5Dgf/ JrTw/KPsiNFsfWEkD2Sns57SP4Fv2pBtqpfEB4wuE9ywaH1S9kX/+1JvAV6JyslK+OzW NBCg== X-Gm-Message-State: AOAM533tGY6qPymzjQ7LLng/1ctr55/s9Y34CcGvu8IAhvIrW8Jx6je7 c4r/1dCOm4gEwi3HNF01/4Csx5EmgbY3aVAhvUIcc4AXL8k/CTmwcytDM8QyN/HsPK6hz5kQgsA RoIeydLl/D9AZtntEuwV8dO6d/jYgQenyhf8RqoP/YpxiY6a0tMOzJpaTUEiJ X-Received: by 2002:a05:620a:40c6:: with SMTP id g6mr7712197qko.226.1619540040616; Tue, 27 Apr 2021 09:14:00 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxaSB+v4nhW1pF8jFSUzXD1x5f/DDzv4u7/+Bwb8/4kHfWIDByTz/eIHQ9VVD180ealMkxeXQ== X-Received: by 2002:a05:620a:40c6:: with SMTP id g6mr7712153qko.226.1619540040220; Tue, 27 Apr 2021 09:14:00 -0700 (PDT) Received: from xz-x1.redhat.com (bras-base-toroon474qw-grc-77-184-145-104-227.dsl.bell.ca. [184.145.104.227]) by smtp.gmail.com with ESMTPSA id v66sm3103621qkd.113.2021.04.27.09.13.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Apr 2021 09:13:59 -0700 (PDT) From: Peter Xu To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Nadav Amit , Miaohe Lin , Mike Rapoport , Andrea Arcangeli , Hugh Dickins , peterx@redhat.com, Jerome Glisse , Mike Kravetz , Jason Gunthorpe , Matthew Wilcox , Andrew Morton , Axel Rasmussen , "Kirill A . Shutemov" Subject: [PATCH v2 23/24] mm/userfaultfd: Enable write protection for shmem & hugetlbfs Date: Tue, 27 Apr 2021 12:13:16 -0400 Message-Id: <20210427161317.50682-24-peterx@redhat.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210427161317.50682-1-peterx@redhat.com> References: <20210427161317.50682-1-peterx@redhat.com> MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=peterx@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 9FDCEE000128 X-Stat-Signature: isdmtb4wju4obdro4wuohpt6tpzp5dec Received-SPF: none (redhat.com>: No applicable sender policy available) receiver=imf21; identity=mailfrom; envelope-from=""; helo=us-smtp-delivery-124.mimecast.com; client-ip=170.10.133.124 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1619540042-908034 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: We've had all the necessary changes ready for both shmem and hugetlbfs. Turn on all the shmem/hugetlbfs switches for userfaultfd-wp. Now we can remove the flags parameter for vma_can_userfault() since not used any more. Meanwhile, we can expand UFFD_API_RANGE_IOCTLS_BASIC with _UFFDIO_WRITEPROTECT too because all existing types now support write protection mode. Since vma_can_userfault() will be used elsewhere, move into userfaultfd_k.h. Signed-off-by: Peter Xu --- fs/userfaultfd.c | 19 ------------------- include/linux/userfaultfd_k.h | 15 +++++++++++++++ include/uapi/linux/userfaultfd.h | 7 +++++-- mm/userfaultfd.c | 10 +++------- 4 files changed, 23 insertions(+), 28 deletions(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index a41e0631af512..a436a1feb10db 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1275,25 +1275,6 @@ static __always_inline int validate_range(struct mm_struct *mm, return 0; } -static inline bool vma_can_userfault(struct vm_area_struct *vma, - unsigned long vm_flags) -{ - /* FIXME: add WP support to hugetlbfs and shmem */ - if (vm_flags & VM_UFFD_WP) { - if (is_vm_hugetlb_page(vma) || vma_is_shmem(vma)) - return false; - } - - if (vm_flags & VM_UFFD_MINOR) { - /* FIXME: Add minor fault interception for shmem. */ - if (!is_vm_hugetlb_page(vma)) - return false; - } - - return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) || - vma_is_shmem(vma); -} - static int userfaultfd_register(struct userfaultfd_ctx *ctx, unsigned long arg) { diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h index fefebe6e96560..95afd4814ab29 100644 --- a/include/linux/userfaultfd_k.h +++ b/include/linux/userfaultfd_k.h @@ -16,6 +16,7 @@ #include #include #include +#include /* The set of all possible UFFD-related VM flags. */ #define __VM_UFFD_FLAGS (VM_UFFD_MISSING | VM_UFFD_WP | VM_UFFD_MINOR) @@ -132,6 +133,20 @@ static inline bool userfaultfd_armed(struct vm_area_struct *vma) return vma->vm_flags & __VM_UFFD_FLAGS; } +static inline bool vma_can_userfault(struct vm_area_struct *vma, + unsigned long vm_flags) +{ + if (vm_flags & VM_UFFD_MINOR) { + /* FIXME: Add minor fault interception for shmem. */ + if (!is_vm_hugetlb_page(vma)) + return false; + } + + return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) || + vma_is_shmem(vma); +} + + extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *); extern void dup_userfaultfd_complete(struct list_head *); diff --git a/include/uapi/linux/userfaultfd.h b/include/uapi/linux/userfaultfd.h index bafbeb1a26245..298fbd4e2d1d3 100644 --- a/include/uapi/linux/userfaultfd.h +++ b/include/uapi/linux/userfaultfd.h @@ -31,7 +31,8 @@ UFFD_FEATURE_MISSING_SHMEM | \ UFFD_FEATURE_SIGBUS | \ UFFD_FEATURE_THREAD_ID | \ - UFFD_FEATURE_MINOR_HUGETLBFS) + UFFD_FEATURE_MINOR_HUGETLBFS | \ + UFFD_FEATURE_WP_HUGETLBFS_SHMEM) #define UFFD_API_IOCTLS \ ((__u64)1 << _UFFDIO_REGISTER | \ (__u64)1 << _UFFDIO_UNREGISTER | \ @@ -45,7 +46,8 @@ #define UFFD_API_RANGE_IOCTLS_BASIC \ ((__u64)1 << _UFFDIO_WAKE | \ (__u64)1 << _UFFDIO_COPY | \ - (__u64)1 << _UFFDIO_CONTINUE) + (__u64)1 << _UFFDIO_CONTINUE | \ + (__u64)1 << _UFFDIO_WRITEPROTECT) /* * Valid ioctl command number range with this API is from 0x00 to @@ -196,6 +198,7 @@ struct uffdio_api { #define UFFD_FEATURE_SIGBUS (1<<7) #define UFFD_FEATURE_THREAD_ID (1<<8) #define UFFD_FEATURE_MINOR_HUGETLBFS (1<<9) +#define UFFD_FEATURE_WP_HUGETLBFS_SHMEM (1<<10) __u64 features; __u64 ioctls; diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 2cd6ad5c3d8f8..3930e56aaefd8 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -445,7 +445,6 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm, err = mfill_zeropage_pte(dst_mm, dst_pmd, dst_vma, dst_addr); } else { - VM_WARN_ON_ONCE(wp_copy); if (!zeropage) err = shmem_mcopy_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr, @@ -682,15 +681,12 @@ int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start, err = -ENOENT; dst_vma = find_dst_vma(dst_mm, start, len); - /* - * Make sure the vma is not shared, that the dst range is - * both valid and fully within a single existing vma. - */ - if (!dst_vma || (dst_vma->vm_flags & VM_SHARED)) + + if (!dst_vma) goto out_unlock; if (!userfaultfd_wp(dst_vma)) goto out_unlock; - if (!vma_is_anonymous(dst_vma)) + if (!vma_can_userfault(dst_vma, dst_vma->vm_flags)) goto out_unlock; if (is_vm_hugetlb_page(dst_vma)) {